From: Wang Hai <wanghai38@xxxxxxxxxx> commit bbbf962d9460194993ee1943a793a0a0af4a7fbf upstream. I got a memory leak report: unreferenced object 0xffff8881191fc040 (size 232): comm "kworker/u17:0", pid 23193, jiffies 4295238848 (age 3464.870s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff814c3ef4>] slab_post_alloc_hook+0x84/0x3b0 [<ffffffff814c8977>] kmem_cache_alloc_node+0x167/0x340 [<ffffffff832974fb>] __alloc_skb+0x1db/0x200 [<ffffffff82612b5d>] wg_socket_send_buffer_to_peer+0x3d/0xc0 [<ffffffff8260e94a>] wg_packet_send_handshake_initiation+0xfa/0x110 [<ffffffff8260ec81>] wg_packet_handshake_send_worker+0x21/0x30 [<ffffffff8119c558>] process_one_work+0x2e8/0x770 [<ffffffff8119ca2a>] worker_thread+0x4a/0x4b0 [<ffffffff811a88e0>] kthread+0x120/0x160 [<ffffffff8100242f>] ret_from_fork+0x1f/0x30 In function wg_socket_send_buffer_as_reply_to_skb() or wg_socket_send_ buffer_to_peer(), the semantics of send6() is required to free skb. But when CONFIG_IPV6 is disable, kfree_skb() is missing. This patch adds it to fix this bug. Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx> Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireguard/socket.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/net/wireguard/socket.c +++ b/drivers/net/wireguard/socket.c @@ -160,6 +160,7 @@ out: rcu_read_unlock_bh(); return ret; #else + kfree_skb(skb); return -EAFNOSUPPORT; #endif } Patches currently in stable-queue which might be from wanghai38@xxxxxxxxxx are queue-5.10/video-fbdev-smscufx-fix-null-ptr-deref-in-ufx_usb_pr.patch queue-5.10/wireguard-socket-free-skb-in-send6-when-ipv6-is-disabled.patch